Necticut



J. ALM AND -J. HUGHES. RUBBER BOOT AND MEN-I00 OF MANUFACTURING THE SAME UNDER DIFFERENTIAL or PRESSURES.

APPLICATION FILED JAN. 20. I920 Patented Feb. 15, 1921.

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UNITED STATES PATENT OFFICE.

JOHN ALI AN D JAMES HUGHES, OF NAUGATUCK, CONNECTICUT, ABSIGHOBB T0 was GOODYELBS METALLIC RUBBER SHOE COMPANY, A CORPORATION OI OOH- aumma Boo'r AND METHOD or MANUFACTURING THE sum trauma nnr or rmassmms.

To all whomit may concern:

Be it known that we, JOHN Ann and J AMES Hnenns, citizens of the United States, both residing at Nau atuck, county of New Haven, and State 0 Connecticut, have invented certain new and useful Improvements in Rubber Boots and Methods of Manufacturing the Same Under Differential of Pressures, of which the following is a full, clear, and exact description.

This invention relatesto rubber boots and a method of manufacturing the same under differential of ressures.

In the manufacture of rubber boots under the so-called differential method, the numerous parts are assembled upon a last, being joined together by the adhesionof certain of their inter-engaging rubber or rubberized surfaces, the parts being rolled down upon the last so as to conform with the contour of the latter. A hollow perforated last is generally employed in the method, so as to b the interior of the last into communication with the fabric lining of the boot, the perforations bein preferably formed at the sole portion of t e last. At a stage in the manufacture of the boot, and lgenerally during the application of heat t ereto to effect vulcanization, the exterior of the boot is subjected to a fluid pressure greater than that of the ressure within the interior of the last an boot, to remove any fluid entrapped between or within the assembled arts of the boot, the died? of this step bemg not only to solidify and compact the boot structure, and therefore prevent -porosity and ly separation, but incidentally to cause the boot to closely hug the last. Inasmuchps the lining of the boot consists of a wear-resisting layer of heavy fabric, rubberized on its interior to effect a permanent bond with the rubber vamp, counter or u r, as the case may be, the effect of the di erential of pressures durmg the heat of vulcanization may .force the rubber coating of the lining through the latter and into eontact with the last.

vulcanization is com leted, the adhesion be- In such case when an the last greatly resists the boot from the last. The mice. aluminum flake.

tween the linin the strip ing 0 use of ta c, soap stone, applied either to the Specification of Letters Patent.

last or the lining as a Patented Feb. 15, 11521.

powder or paint to overcome this problem is not desirable for several reasons, among which is the fact that such materials tend to work the seams and prevent secure oints be ng made between the parts of the met, and the further fact that such materials tend to render the lining non-porous and thus resist the differential treatment.

By our invention we overcome the probleln in question by inter-posing between the lin ng of the boot and the last, a porous material which generally will become incorporated into the boot structure by adhesion to the lmmg, but which may not be strain resistmg or possess any functional action in the boot, and which will resist the passage of rubber from the lining to the last, and thus will act as a guard or protection for the latter. The material is preferably a chea hght-woven fabric which is sulficien y strong to withstand the strain necessary to all it from the surface of the lining, when esired, and yet which may possess such slight resistance to wear, that, when not removed from the boot after vulcanization, it will rapidly disintegrate and expose the wear-resisting lining beneath it. In some cases, the protecting material may be placed upon the last prior to the assembly of the parts of the boot thereon, but the material is preferably applied directly to the boot lining prior to the amembly of the latter upon the last.

For a more complete understandin of the referred method, reference is ma e to the rawings, in which:

F igure 1 is a plan view of the leg por-.

tion of a boot.

Fig. 2 is a plan view of the vamp. Fig. 3 is an elevation partly in section of the boot in assembled condition upon a last,

the latter being provided with means for sole 14,"and t e heel 15, then rion, its marginal portions 1 such as cheese-cloth. When the lining 3 is I rubberized on both sidlls,the' rotecting shee 4 may be assembled in the g structure a. as to be held irPplace during manipulation. of the latter, by passing the leg structure lhrough a warm calender, And where the 8' in contaet'with the strain resisting sheet 2, its margin or its entire surface may "covered with sufficient cement to hold thcsheet in place durin the assembly of the',boot. he vamp, bur t.up in like manner, comprises the sheeted-rubber vamp iece 5, the rubberized fabric lining 6,.whic .acts as 'a strain and wear-resisting member, and the protectin sheet 7.. It will be understood that in t e assembly of the parts upon the last, any customary or desired method or procedure may be em 10 ed. k

In the boot shown in t e drawin the leg structure is applied to the last an its margins 8 are over apped and united. Next the margins 9 are turned in upon an insole (not shown). The vamp is then placed in posibeiug lapped upon the le portion and its mar ll Heingturnecfin. upon the insole. ext the quarter ply 12 of sheeted rubber is placed is position, as shown in Fig'. 3, and is turned :9. upon the insole. When desired, the promoting sheet may be coextensive with the fming so as to be turned in with the latter of the outupon the insole. The assembl soles, includin the smooth so e 13 and tap takes place in the customary manner. It will thus'be seen thatthe protecting sheet is disposed intermediate the lining and the last through mt the interior ofthe boot. v

The last is provided with an aperture 16 to receive the nipple 17 of a pipe 18, which in practice may connected with a suction device for producing a reduced pressure,

that is to so a partral vacuum, wrthinthe interior of t 0 boot.

While we preferably employ a light fabric as the protecting sheet or false lining, the materia may be any other thin, flexible porous material, fibrous or non-fibrous in its character. In some cases the material may a be placed upon the last prior to the assembly of the boot, but it is preferably applied directly to the lining before the latter is lasted with the remaining elements of the boot.

In ential of pressure will; as 'hereiubeforestated, force the boot firml in contact with the walls of the last, an rubber willbe drawn toward the last from the rubberized llnlng. The protecting sheet, or false lining, however, will receive the rubber and therefore 7 adhesion between the boot and the last will be revented. 0 r

a boot manufactured under the dlffgb'rieis frictioned only on the side,

'boot the two rubber surfaces of possess identical characteristics, in the twothe vulcanizing operation, the difl'era'erential process, the various layers of rubber and fabric adhere to each other with much greater tenacity than is the case with a boot made by the ol adhesion of the various layers is secured by pressure applied by the manipulation of a and roller. In a boot made by the old method, the fabric plies strip other with. varying or unequal resistance, showing that the a hesion between any two oppose plies or layers is not of the umform tenaclty. The characteristic of a boot manufactured under the difl'ereritiaL is that the adhesion betweenany two opposed layers rs of the same tenacity through out.

By our invention'we are able to produce a novel boot b a coating the wear-resisting lining with rub r on both surfaces, and by vulcariizing these twosurfaces simultane ously with the remainin parts of the boot, and under a'dili'erentia of pressures, the protecting sheet or. false lining bein preferably stripped from the interior of t e boot after vulcanization of the latter. -Such a boot has great utiliiyg'in that it possesses the characteristics 0 a boot vulcanized under a differential of a uniform vulca -rubber coating upon the exposed surface of the linin which prevents the rotting of the letter W en the a cot is subjected to severe use. The boot is markedly superior to one in which the exposed linmgcoat rs applied after vulcania'ation of the boot, in which case'the boot must withstand a second cure with the consequent weakening of its structure. Whereas In our the lining cure boot the inner .rubber surface will be different from that of the exposed rubber surface.

Having thus described our invention, what we claimand desire to protect by'Letters Patent is: i 4

1. In the manufacture of a boot comprising a sheeted rubber exterior and a rubberized fabric wear-resistin lining, assemblin the boot upon a last and placrnga flexib e sheet intermediate the boot linin and the last, and vulcanizing the boot un er a.dif-' ferential of ressures, the greater ressure bein ap lie "to the exterior of the cot.

2. n t e manufacture of a boot'comprising an exterior of sheeted rubber and a wearresisting lining of rubberized fabric, assembling the boot upon a pervious last and placing a false lining intermediate the boot lining and the last, and ada ted to permit the passage of fluids from t e boot to the interior of the last and to impede the passage of rubber from' the lining'to the last, and.

the step of vulcanizing the boot under a differential of pressures the greater ressure being applied to the exterior of the from "each process tenures and includes 3. The methud of making rubber feetwear having a coating of rubber on the in terior of the strain resisting lining, (lfimpliv ingthe steps of building up the article ef several plies of sheeted material including strain resisting lining 0i rubberized fabric. and placing said plies on a last, together with a parting sheet interposed between the article and thelast,and then vulbuniziug the article under pressure and maintaining a greater pressure on the exterior thereei ts press the iliiierent plies toward each other and toward the iast.

4. The method of making; rubber boats having a coating of rubber on the interimof the strain resisting lining, cemprising the steps of assembling: the boat LIPGD. pervieus lust and placing: :1 false iiniu fabric between the boot parts anti the laet, and then vulcanizing the boot under a ii ferential of pressure, the greater pressure being applied to the exterior ef the beet 5. In the manufacture of a beat eoreprie ing a sheeted rubber exterior and a rubberized fabric wearresisting lining assembling surfaces 'llbllil iel'lric lining,

the beet upon a rvious last and placing a. flexible pereus 5 met intermediate the boo iinng and the last, vulcenizing th e riifierentielof pressures,- the greater being a iplied tn the exterior of the 1 9e) that minis-er from the lining will be iiuet seid sheet, removin the boot a iii-3e, and stripping the 5 eat from r 1g. p

A vulcanized rubber boot com used-of (ii rulcanizerl rubber and abric in 5 t e adhesion between oyilposed layers e1 Z-iiu same teneeity throug out, and including a fabric iiiiiiig having both of its coated with rubber vulcanize simuitimeeualy.

A rubber boot comprising-an exterior r5 eheeted rubber a wear-resisting rubberand a false porous lining eugerpeeerl upon the letter.

C! gned at Neugetuek, Connecticut, this 12 day at January, 19%.

JOHN ADM. JAMES HUGHES. 

